I have planned to create some application for which I need to capture human whole body with camera and to modify it and then to display it. I am wondering what camera I should buy for this? It should be HD cam or any other? I am just empty about that. This is going to be my first face/body detection project so I am not sure where to start.
We'd need more information to give a good answer. Your real restrictions aren't going to be your application, but what OS, programming language, and libraries you're going to use. Once you decide on those, you can start looking for camera compatibility specifications. For example: Linux OpenCV Camera Compatibility. From there you'll want to look into each camera to find out if it meets your specific project needs and if it's in your price range.
I have no idea from a programming perspective but, for indoors use in general regardless of application, you'd want to make sure it has exceptionally good low-light performance, like Sonys Exmor R sensors and similar.
Stuff are a lot easier when you don't have to do studio-style lighting to get rid of noise ^^